Manufacture of useful products by means of friedel and crafts reaction



Jan. 17, 1928. 1,656,575

H. G. STONE ET AL l MANUFACTURE OF USEFUL PRODUCTS BY MEANS OF FRIEDEL AND CRAFTS HEACTIOBI Filed Dec. 2S, 1923 (GAS INTAKE) 15 Patented Jan.- 17, `19128.

UNITED STATES 1,656,575 PATENT ormca.

HERBERT G. STONE AND BIERIARDV H. JACOBSON, F CHARLESTON, WEST VIRGINIA,

ASSIGNORS TO. E. C. KLIPSTEIN & SONS COMPANY, OF NEW YORK, N. Y., A. COB- PORATION 0F NEW JERSEY.

MANUFACTURE or USEFUL PRODUCTS BY MEANS or FRIEDEL AND CRAFTS nEAcTIoN.'

Application led December 28, 1923. Serial No. 653,242.

This invention relates to improvements in manufacture of useful products by means of Friedel and Crafts reaction; and .it relates more particularly to processes 1nl which 5 Vproducts useful in the manufacture of dyestuffs are synthetically prepared by reaction between an aromaticl compound-and another compound (either aromatic or not) in .the presence of anhydrous aluminum chlorid un- 410 der such reacting conditions thatthe aluminum chlorid compound of a desired resultant aromatic derivative is obtained in a simpler and more economical manner than has' been possible heretofore. i

As will appear hereinafter, the invention is broadly applicable to syntheses involving the Friedel and Crafts reaction. One of its most important practical applications at the present time is for tl're synthetic production of an intermediate, namely o-benzoyl-benzoic acid, from which anthraquinone can be made in accordance with known methods. This particular phase of the broad invention will therefore be more particularly emphasized in the following description by way of a concrete explanatory example typically illustrating the underlying principles involved.

One of the important known commercial methods of manufacturing anthraquinone involves as its iirst stage the preparation of the intermediate product o-benzoyl-benzoic acid by reaction between benzol, phthalic anhydrid and anhydrous aluminum chlorid, giving an aluminum chlorid compound of o-benzoyl-benzoic acid, which, upon treatment with water, acid or alkali, breaks down yielding o-benzoyl-benzoic acid orv its salts. The second stage of this manufacturing method linvolves dehydrating the o-benzoylbenzoic acid, as by heating under proper conditions, to reduce anthraquinone. present invention hasto do more particularly with improvementsin carrying out the irstdstage of this general method above outine Heretofore, the first stage of the aforesaidV method of making anthraquin'one has presented many dilculties. Accordingto the procedure heretofore in general use, it has been necessary to socharge the benzol, phthalic anhydrid and aluminum chloride into the'reaction vessel that serious trouble is encuntered from fuming. Even if one of the solids ('phthalic anhydrid or aluminum Thel '. another vessel for further treatment. Moreover, the breaking down of the resultant alu- 05 minum chloridcompound to give o-benzoylbenzoic acid, whether water, or aqueous'acid or alkali be used for this purpose, together with the subsequent distillation of the large lexcess of benzol employed in this prior known method, involves great technical difficulties due particularl to the large vol-l umes of hot, wet hy rochloricacld gas evolved from hydrolysis of the aluminum chlorid. ,The corrosive action is so extreme that the apparatus problem becomes serious. Even lead linings in the reactors do notl withstand this excessive corrosive action, and asv a consequence the extensive repairs necessitated, coupled with resultant loss of 80. time due to shut-downs, makes this method of operation very expensive. l

It is a general object of the present invention to avoid the diiculties inherent in the rior known method hereinabove outline by providing `a novel process which, besides being simpler and more readily carried out, is also characterized by eater economy of operation and larger yield of the desired products. cordance-with the invention, the phthalicv anh drid and aluminum chlorid are thoroug ly commingled in a suitable reactor, y

most desirably in a rotary mill which grinds these non-reacting solid materials into fine powder and thus brings them into very intimate contact in a' substantially uniform mixture.-A The rotary mill, Iwhich is desirably of the ball-mill type, is provided with inlet and outlet pipes for liquid and gases and with suitable closures, so that it constitutes a closed reactor. Either during or after thorough mixing of the non-reacting solid reagents in the mill, the benzol' can then be introduced through a suitable inlet pipe without stopping rotation of the mill. The resultant. fumes, including substantially dry hydrochloric acid gas, are lead away through In proceeding in ac- 90 v a suitable outlet pipe and absorbed in water or otherwise disposed `of without escaping into the atmosphere. Rotation of the grinding mill is continued, and after the reaction is substantially complete, any excess of benzol in the pasty reaction mass can be evapo rated by passing a current of an inert gas,

such as substantially dry air, through the rotating mill. As the operation continues, the reaction mass gradually becomes dry and is finely powdered by the action of the grind-v ing balls. The product obtained in this dry pulverulent' form constitutes a new article of manufacture. It probably has the constitution:

In a specific example, using the apparatus that is more or less diagrammatically illustrated in side elevation in the accompanying drawing, the procedure may be as follows: Into a suitable reactor, in this instance a horizontal rotary ball mill 10, which is about ten feet long and three feet in diameter, are charged 400 pounds of phthalic anhydrid and` 800 pounds of anhydrous aluminum chlorid. This mill has hollow trunnions 11 and 12, suitably mounted for rotation in bearings 13.' The rotary mill is arranged to be rotated from a suitable source of power through suitable'reduction gearing at a suitable speed which may desirably be about 23 R. P. M. From a storage tank 14 for benzol, a pipe 15, valved at 16 and 17, extends through stufling box'18 into hollow trunnion .11 aforesaid, whereby benzol may be run into the ball mill. rAn air or gas supply pipe19, Valved at 20, leading from any suitable source of air under pressure, enters pipe 15 and extends axially therewithin for conducting air into the ball mill through trunnion l1. The opposite hollow trunn1on12 is also provided with a stufling box 21 through which extends a gas offtake pipe 22 valved at 23, said pipe leading to gas-absor ing, means comprisin in .this instance a suitable vessel 24 containing water below the surfacevof which the oiftake pipe discharges. A branch pipe 25, valved at 26,. Iis connected to ,an air pump or other vacuum-producing means tnot shown).

The charge of .phth'alic anhydrid and anhydrous aluminum Jchlorid having been placed in the ball mill and the man-head closure 27 having been secured-in position, valves 20 and 26 beingclosed and valve 23 open, the mill is rotated and 400 poundsf'of benzol are run into themill fromthe storage or supply reservoir 14. The reactionv starts vimmediately and HCl gas is evolved, said gas passing out of the mill through ipe 22 and being absorbed in water in container 24.

After all the benzol is added, the. mill is advantageously rotated for several hours tion as follows:

. The rotary effect and the grinding action of the balls thoroughly mixes the reactive compounds and favors substantially complete reaction. The material in the mill having become a lpasty mass, the valve 23 is now closed and the connections to air and vacuum are established by opening valves 2O and 26, respectively, rotation of the mill being continued meanwhile. The resultant passage of air through the mill evaporates and removes any excess benzene (benzol) remaining therein, the asty residue in the mill gradually solidifying and being ground up by the iron balls to a fine powder. The yield amounts ina typical instance to approximately 1,343 pounds.

It is to be noted that the hydrochloric acid gas evolved in the reactor during the operation above described is substantially dry and therefore does not attack the metal of the mill or grinding balls which may therefore be iron or the like. The air or other inert gas passed through the mill to drive of eXcess-benzol should not contain moisture tosuch an extent as to render the hydrochloric acid gas actively corrosive. To this end such air or gas may be preliminarily dried, if necessary ordesirable, before passing it into the reactor.

The reaction mass having been ground to a substantially dry powder as above described, the mill is then stopped, the manhead 27 is removed and a grating substituted therefor, and the mill is emptied of its contents. For example, the material may be emptiedinto a hopper and thence into barrels .or other containers for storage or shipment. Treatment of thisnovel pulverulent intermediate by dropping the same,l into dilute hydrochloric'acid results in splitting off aluminum chlorid and producing o-benzoyl-benzoic acid, probably according to the following reaction:

The crude o-benzoyl-benzoic acid thus produced is separated from the aluminum chlo rid solution by filtration and is then dried for use, in this instance for use in the manufacture of anthraquinone. The yield of obenzoyl-benzoie acid under the conditions by weight of benzene (benzoi) to each part of phthalic anhydrid. In order to render the process commercial, it has therefore been necessary to recover this very large excess by steam distillation and to dry the recovered benzene for re-iise. The present iiivention renders all this unnecessary, because by the new process it is possible to get thorough contact with only one part of benzene toeach part of phtlialic anhydrid. This amount of benzene is still slightly greater than is. required by theory, but the excess is so slight that, even it' it is allowed to go to waste, the loss amounts to less than the losses involved in the old process requiring recovery.

The old process requires steam heating and retluxing in carrying out the reaction. In the new process no heating is required and a substantial economy is thereby effected, not to mention the fact that the operation is also simplified.

In the old process, after the reaction is complete, it is necessary to add aqueous alkali or acid directly to the reactor in oi'- der to break down the aluminum clilorid compound of o-benzoyl-benzoic acid and to render the discharging of the reactor feasible. It is this step, together with the subsequent step of steam distil-ling the resultant mass to remove the large excess of benzene which is so destructive to the apparatus.r

lliis step is completely eliminated' in the new process. The elimination of this principal item of repair by the new. process cutsI the maiiitenace cost to a minimum and makes it feasible to maintain substantially continuous operation and production.

1n the process heretofore commonly used, one of the solid yreagents and the liquid reagent were tirst charged into a reactor and then the other solid reagent was added slowly in the i'ace ot evolved HC1 gas. According to the new process, by charging in the non-reacting reagents (both solids in this instance) before adding the reactive liquid reagent, substantially all fuming of an obnoxious character is eliminated and the technical operation of the process is -thereby greatly simplitied.

.Operation on a commercial scale for a substantial period of time shows that the new process averages about ten higher yields than the old process.

Since the new process is substantially anhydrous until after the Friedel and Crafts reaction is completed and t-he aluminum chlorid compound is discharged from the reactor, the necessity for having steam and Water connections to the reactor is do-ne away With and the danger of leaky steam or water valves spoiling a batch is entirely eliminated. While the new process has been described with particular reference to the manufacture v per cent of an intermediate useful for production of anthraquinone, it can be extended in general with similarly satisfactory results to the carrying out ot other syntheses involving the Friedel and Crafts reaction, with such minor moditications in detailed procedure as may be occasioned by the difference in the character ot' the reagents or the reacting inat-erialsI involved in any given case. For example, thel process can be employed for the manufacture of derivatives of anthraquinone, such as methyl-anthraquinone, cliloranthraquinone and thelike; also in general for the manufacture of useful pioducts by t-he Friedel and Cra't'ts reaction where the ieagents comprise anhydrous aluminum chlorid, an aromatic compound reactive therewith, and another organic compound relatively non-reactive toward aluminum chlorid. Examples of such uselul'products are acetophenone, nie-tliyl-acctophenone benzophenolic, etc. ln thc manufacture ofinethylanthraquinone, for instance, it is only necessary to substitute the homologous liquid benzene hydrocarbon, toluene, for benzene in the procedure above described. Vhere the two reagents other than aluminum chlorid.

are both liquids, as is the. case iii the preparation ot acctophcnonc and bcnzophenone, for example, the materials initially charged into the rotary mill should be anhydrous aluiiiiimm clilorid and the liquid reagent that is relatively non-reactive therewith, such liquid being acetyl chlorid, for example, in the one case, and benzoyl clilorid in the other; after which bcnzol is run int-o the reactor as already described for the manufacture of obei'izoyl-benzoic acid. For the sake of a generic terni, the terni acidyl compound may bc conveniently employed to includevsu'ch coinpounds` as phthalic anhydrid, acetyl clilorid, benzoyl chlorid, and the like. It is evident, however, that the compound to be employed in the synthesis with the benzol or other aro'- i matic compound is not necessarily an acidyl compound.

'llie terni aroyl will be used to designate generically the grouping in which X is an aryl radicle such as phenyl, tolyl, naphthyl, or the like.

It is to be understood that a practical detailed procedure is hereinabove set forth and descriptive legends appear on the drawing solely by way of an explanatory example to enable, a clear understai'iding of the principles upon which the invention is based, but that` the invention, broadly considered, is not restricted lto such details, being susceptible of considerable variation while still real- `izing in whole or in substantial measure the benefits and advantages aforesaid.

What is claimed is:

les

1. In the manufacture ofA intermediates useful in the preparation of anthraquinone dyestuffs, the process which comprises grinding together phthalic anhydrid and, anhydrous aluminum chlorid and introducing a liquid benzene hydrocarbon into the mlxture, leading off resultant reaction fumes, and evaporating ofi' excess of said benzene hydrocarbon while continuing the grinding to obtain a substantially dry, finely divided solid reaction product.

2. In the manufacture of intermediates useful in the preparation of anthraqumone dyestuffs, the process which comprises grinding together a charge coniprlsing phthahc anhydrid, anhydrous aluminum chlorid, and a liquid benzene hydrocarbon, until the reaction is substantially complete, and evaporating off excess of said benzene hydrocarbon while continuing the grinding to obtain a substantially dry, finely divided product.

3. In the manufacture of useful benzol derivatives, lthe process which comprises grinding a mixture of phthalic anhydrid and anhydrous aluminum chlorid and introducing benzol into the mixture, continuing 'the grinding for several hours, evaporatlng oif excess benzol, and obtaining the resultant aluminum chlorid compound of ortho-benzoyl-benzoic acid in substantially dry a1' d finely divided solid form.

4. In the manufacture of useful benzol derivatives, the process whichA comprises grinding a mixture of anhydrous aluminum chlorid with phthalic anhydrid while introducing benzol into the mixture, leading 'i away resultant reaction fumes, and evaporating'excess benzol substantially without introducing moisture into the reaction mass, the grinding being continued until the reaction, mass is reduced to substantially dry pulverulent condition.

5. In the manufacture of useful benzol derivatives, the process which comprises charging phthalic anhydrid and anhydrous aluminum chlorid into a rotary grinding mill, then chargingr benzol into the mill, rotating the mill to eii'ect intimate contact of the charged materials while leading away resultantreaction fumes, continuing rotation of said mill and passing a current of a gas therethrough until the excess of kbe'nzol is substantially removed and the reaction mass has been reduced tonely divided solid condition. i

6. The process as claimed in claim 3, further characterized byV the fact that the reacting ingredients are employed in the approximate proportions, by Weight, of l part phthalic anhydrid, 2 parts anhydrous aluminum chlorid, and 1 part benzol. y

7. The" process as claimed in claim-` 4, further characterized by the fact that the reacting ingredients are employed in the approximate proportions, by weight, of 1 part phthalic anhydrid, 2 parts anhydrous aluminum chlorid, and l part benzol.

8. The process as claimed in claim 5, further characterized by the factl that the reacting ingredients are employed 1n the approximate proportions, by Weight, of 1 part phthalic anhydrid, 2 parts anhydrous aluminum chlorid, and 1 part benzol.

9. In the manufacture of useful products by the Friedel and Crafts synthesis, where the reagents comprise anhydrous aluminum chlorid, an aromatic compound reactive therewith, and another organic compound relatively non-reactive toward aluminum chlorid but capable of taking part in the desired synthesis, the process which comprises commingling anhydrous aluminum lchlorid with said relatively non-reactive compound, then adding said aromatic compound to the mixture under reacting conditions such that the reaction mass is at least partially liquid, and reducing the reaction mass to substantially dry comminuted condition while leading away volatilized matter.

l0. In the manufacture of useful benzene derivatives by means of the Friedel and Crafts reaction, the process which comprises ithoroughly commingling anhydrous aluminum chlorid andan organic acidyl compound capable of functioning in said reaction, introducing into the mixture a benzene hydrocarbon whose derivative itis desired to produce, and grinding the resultant mass under anhydrous conditions and without application of heat to effect the desired reaction.

1l. In the manufacture of useful products by the Friedel and Crafts reaction from a loo liquid compound of the benzene series and an organic acidyl compound capable of functioning in said reaction, which comprises commingling anhydrous aluminum chlorid with such acidyl compound land adding to the mixture such liquid compound of the benzene series, agitating the mixture, evaporating surplus liquid therefrom, and comminuting the resultant solid aluminum chlorid compound.

12. As a new article of manufacture, an aluminum chlorid compound of an aroylbenzoic acid, in the forml of a substantially dry, finely divided solid. 13. As a new article of manufacture, an yaluminum chlorid compound of an o-aroylbenzoie acid, in the form of a substantially dry, finely divided solid. f

14:. As a new articleof manufacture, an aluminum chlorid compound of o-benzoylbenzoic acid. in the forni-"of a substantially dry, finelyv divided solid.

In testimony whereof we hereunto aiix our signatures.

HERBRT e. sronn. BERNARD H. JaooBsoN, 

